Let's divide 643669 by 16
We want to figure out the number of times 643669 can be divided by 16.

Moving on to step 1:
If we divide 6 by 16, we get 0 and a remainder of 6.
The next digit of our result is 0. 
Result so far: 0.0
Subtracting 0 from 6 leaves us with 6.
Fetch the next digit (4) from the dividend, attach it to 6 and continue: 64 / 16

Step 2:
When dividing 64 by 16, we get 4 with a remainder of 0.
Write down 4 as next digit of the result. 
Result so far: 4.0
Deduct 64 from 64 and we're left with 0.
Fetch the next digit (3) from the dividend, attach it to 0 and continue: 3 / 16

Moving on to step 3:
When dividing 3 by 16, we get 0 with a remainder of 3.
Record the quotient 0 as the next digit in the result. 
Result so far: 40.0
If we take 0 away from 3, we end up with 3.
Grab the next digit (6) from the dividend, add it to 3, then carry on: 36 / 16

Moving on to step 4:
The number 16 fits into 36 2 times, leaving a remainder of 4.
The next digit of our result is 2. 
Result so far: 402.0
Subtracting 32 from 36 leaves us with 4.
Include the next digit (6) from the dividend after 4, then repeat: 46 / 16

Let's proceed to step 5:
If we divide 46 by 16, we get 2 and a remainder of 14.
Put 2 as the next digit of the answer. 
Result so far: 4022.0
Subtract 32 from 46 to get 14.
Append the next digit (9) from the dividend to 14 and continue with: 149 / 16

Step 6:
16 can be fit into 149 9 times, resulting in a remainder of 5.
Put 9 as the next digit of the answer. 
Result so far: 40229.0
If we take 144 away from 149, we end up with 5.
Since there are no more digits in the dividend, we add a zero to the remainder making it 50, and continue the process.

Step 7:
If we divide 50 by 16, we get 3 and a remainder of 2.
The next digit of our result is 3. 
Result so far: 40229.3
Subtract 48 from 50 to get 2.
Since there are no more digits in the dividend, we add a zero to the remainder making it 20, and continue the process.

Let's proceed to step 8:
16 goes into 20 1 times with a remainder of 4.
The next digit of our result is 1. 
Result so far: 40229.31
The remainder is 4 after subtracting 16 from 20.
Since there are no more digits in the dividend, we add a zero to the remainder making it 40, and continue the process.

Advancing to step 9:
The number 16 fits into 40 2 times, leaving a remainder of 8.
Write down 2 as next digit of the result. 
Result so far: 40229.312
If we subtract 32 from 40, we get 8.
Since there are no more digits in the dividend, we add a zero to the remainder making it 80, and continue the process.

Advancing to step 10:
If we divide 80 by 16, we get 5 and a remainder of 0.
Write down 5 as next digit of the result. 
Result so far: 40229.3125
Subtracting 80 from 80 leaves us with 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

Moving on to step 11:
When dividing 0 by 16, we get 0 with a remainder of 0.
Use 0 as the next digit of our solution. 
Result so far: 40229.3125
The remainder is 0 after subtracting 0 from 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

Let's proceed to step 12:
16 can be fit into 0 0 times, resulting in a remainder of 0.
The number 0 becomes the next digit in our result. 
Result so far: 40229.3125
If we subtract 0 from 0, we get 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

The quotient of the division is 40229.3125, and the remainder is 0.0.